| Canonical Name: | VER J2019+407 |
| TeVCat Name: | TeV J2019+407 |
| Other Names: | SNR G78.2+2.1/Gamma Cygni
1FGL J2020.0+4049
SNR G78.2+2.1
2HWC J2020+403 |
| Source Type: | UNID |
| R.A.: | 20 20 04.8 (hh mm ss) |
| Dec.: | +40 45 26 (dd mm ss) |
| Gal Long: | 78.33 (deg) |
| Gal Lat: | 2.49 (deg) |
| Distance: | |
| Flux: | 0.037 (Crab Units) |
| Energy Threshold: | 320 GeV |
| Spectral Index: | 2.37 |
| Extended: | Yes |
| Size (X): | 0.23 (deg) |
| Size (Y): | 0.23 (deg) |
| Discovery Date: | 2009-11 |
| Discovered By: | VERITAS |
| TeVCat SubCat: | Default Catalog |
Source Notes:
Source Location:
From
Weinstein et al. (2013) and
Aliu et al. (2013):
- R.A. (J2000): 20h 20m 04.8s
- Dec. (J2000): +40d 45' 36"
- Statistical uncertainty: 0.03 deg
- Systematic uncertainty: 0.018 deg
From
Weinstein et al. (2011):
- R.A. (J2000): 20h 20m 00.0s
- Dec. (J2000): +40d 49' 12"
From
Weinstein et al. (2009):
- R.A. (J2000):20h 19m 52.8s +/- 0.017 deg
- Dec. (J2000):40d 47' 24.0" +/- 0.023 deg
Source Extent:
From
Weinstein et al. (2013) and
Aliu et al. (2013):
- fitted extension of 0.23 deg +/- 0.03 deg (stat) +0.04 deg (syst) -0.02deg (syst)
- seems to be the radius
From
Weinstein et al. (2011):
- intrinsic extension of 0.18deg +/- 0.03deg(stat) +0.02deg -0.01deg (syst)
From
Weinstein et al. (2009):
- semi-major axis: 0.16 +/- 0.028 deg
- semi-minor axis: 0.11 +/- 0.027 deg
- no information on the angle provided
Spectral Information:
From
Weinstein et al. (2013) and
Aliu et al. (2013):
- Spectral index: 2.37 +/- 0.14(stat) +/- 0.20 (syst)
Flux:
From
Weinstein et al. (2013) and
Aliu et al. (2013):
- 3.7% of the Crab Nebula flux above 320 GeV
Distance:
From
Leahy, Green & Ranasinghe (2013):
- "The HI absorption spectrum is used to obtain a distance limit on
the SNR of 2-4 kpc." (for G78.2+2.1)
Source Association:
From
Piano et al. (2019):
- The authors analysed data from the AGILE-GRID from the region of SNR
G78.2+2.1 (Gamma Cygni).
- "By analyzing the averaged emission on the whole angular extent of
the SNR, we found that a lepton-dominated double population scenario
can account for the radio and gamma-ray emission from the source."
- "In particular, the MeV-GeV averaged emission can be explained
mostly by Bremsstrahlung processes in a high density medium, whereas
the GeV-TeV radiation by both Bremsstrahlung (E_gamma <= 250 GeV) and
inverse Compton processes (E_gamma >= 250 GeV) in a lower density
medium."
From
Abeysekara et al. (2017):
- "Source 2HWC J2020+403 is likely associated with VER J2019+407 (
Aliu et al. 2013).
TeV emission from this source is unidentified, and potentially
associated with the SNR G78.2+2.1 (e.g.,
Fraija & Araya 2016) or the
gamma-ray pulsar PSR J2021 +4026 (E-dot = 1.2 x10e35 erg s−1,
d = 2.1 kpc, age = 77 kyr). The SNR G78.2+2.1 (Gamma Cygni) is
detected as extended by Fermi-LAT, and reported in both the 3FGL and
the 2FHL catalogs. The flux observed by HAWC is higher than the one
reported from VER J2019+407. HAWC may be measuring multiple emission
components."
From
Fraija & Araya (2016):
- "Analysis of gamma-ray emission from the supernova remnant G78.2+2.1
(gamma Cygni) with 7.2 years of cumulative data from the Fermi-LAT
telescope shows a distinct hard, bright and extended component to the
north of the shell coincident with the known TeV source VER
J2019+407. "
From
Aliu et al. (2013):
- the source is located within the radio shell of the supernova
remnant SNR G78.2+2.1
From
Weinstein et al. (2009):
- Possibly associated with Gamma Cygni SNR (G78.2+2.1)
From
Weinstein et al. (2011):
- suggest as a possible explanation for the gamma-ray emission "particle
acceleration (either hadronic or leptonic) within the SNR shock" (SNR G78.2+2.1)
Seen by: VERITAS, ARGO-YBJ, HAWC
-
MHD decomposition explains diffuse gamma-ray emission in Cygnus X
Fornieri, Ottavio and Zhang, Heshou, arXiv e-prints parXiv:2210.15542 (2022) [LINK]
-
Diffuse gamma-ray emission in Cygnus X: Comments to Fornieri & Zhang 2022
Yan, Huirong and Pavaskar, Parth, arXiv e-prints parXiv:2211.17057 (2022) [LINK]
-
Diffuse gamma-ray emission in Cygnus X: Comments to Yan & Pavaskar
Fornieri, Ottavio and Zhang, Heshou, arXiv e-prints parXiv:2212.01333 (2022) [LINK]
-
HAWC observations of the acceleration of very-high-energy cosmic rays in the Cygnus Cocoon
Abeysekara, A.U. et al., Nature Astronomy p (2021) [LINK]
-
AGILE study of the gamma-ray emission from the SNR G78.2+2.1 (Gamma Cygni)
Piano, G. et al., arXiv e-prints parXiv:1905.01255 (2019) [LINK]
-
Modeling the non-thermal emission of the gamma Cygni supernova remnant up to the highest energies
Fleischhack, H. for the HAWC Collaboration, International Cosmic Ray Conference 36 p675 (2019) [LINK]
-
A Survey of TeV Emission from Galactic Supernova Remnants with HAWC
Fleischhack, H. for the HAWC Collaboration, International Cosmic Ray Conference 36 p674 (2019) [LINK]
-
X-ray study of Variable Gamma-ray Pulsar PSR J2021+4026
Wang, H.H. et al., ArXiv e-prints p (2018) [LINK]
-
A Very High Energy Gamma-Ray Survey towards the Cygnus Region of the Galaxy
The VERITAS Collaboration et al., ArXiv e-prints p (2018) [LINK]
-
Fermi LAT observation of VER J2019+407
Araya, M. and Fraija, N., ArXiv e-prints p (2017) [LINK]
-
The 2HWC HAWC Observatory Gamma-Ray Catalog
Abeysekara, A.U. et al., ApJ 843 p40 (2017) [LINK]
-
The GeV counterpart of VER J2019+407 in the northern shell of the supernova remnant G78.2+2.1 (gamma Cygni)
Fraija, N. and Araya, M., ArXiv e-prints p (2016) [LINK]
-
Suzaku Observation of the Fermi Cygnus Cocoon: Search for a Signature of Young Cosmic-Ray Electrons
Mizuno, T. et al., ArXiv e-prints p (2015) [LINK]
-
Latest results from the ARGO-YBJ experiment
Di Sciascio, G. and for the ARGO-YBJ Collaboration, ArXiv e-prints p (2015) [LINK]
-
The VERITAS Survey of the Cygnus Region of the Galaxy
Popkow, A. and for the VERITAS Collaboration, ArXiv e-prints p (2015) [LINK]
-
VERITAS Observations of the Vicinity of the Cygnus Cocoon
A.Weinstein for the VERITAS Collaboration, ArXiv e-prints p (2013) [LINK]
-
Discovery of TeV Gamma-Ray Emission toward Supernova Remnant SNR G78.2+2.1
Aliu, E. et al., ApJ 770 p93 (2013) [LINK]
-
X-ray and Radio Observations of the gamma Cygni Supernova Remnant G78.2+2.1
Leahy, D.A. et al., ArXiv e-prints p (2013) [LINK]
-
Recent VERITAS Results on VHE Gamma-ray Sources in Cygnus
Ong, R.A. and for the VERITAS Collaboration, ArXiv e-prints p (2013) [LINK]
-
VER J2019+407 and the Cygnus Cocoon
Cardenzana, J.V. and for the VERITAS Collaboration, ArXiv e-prints p (2013) [LINK]
-
TeV gamma-ray survey of the Northern sky using the ARGO-YBJ detector
The ARGO-YBJ Collaboration et al., ArXiv e-prints p (2013) [LINK]
-
The cosmic-ray and gas content of the Cygnus region as measured in gamma rays by the Fermi Large Area Telescope
the Fermi LAT collaboration, ArXiv e-prints p (2011) [LINK]
-
The Fermi-LAT view of cosmic rays and interstellar gas in the Cygnus region: a not so special spot of the Local Arm
Tibaldo, L. et al., ArXiv e-prints p (2011) [LINK]
-
Detection of VER J2019+407 (G78.2+2.1) and Tycho's Supernova Remnant with VERITAS
Weinstein et al. for the VERITAS Collaboration, ArXiv e-prints p (2011) [LINK]
-
Recent Observations of Supernova Remnants with VERITAS
Weinstein, A. et al., ArXiv e-prints p (2011) [LINK]
-
The VERITAS Survey of the Cygnus Region of the Galactic Plane
Weinstein, A. and for the VERITAS Collaboration, ArXiv e-prints p (2009) [LINK]
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